Sections of grating or grates, whether of metal, or fiberglass reinforced molded resin, are often used in forming structural walkways or floors. Each section of grating requires proper positioning in place and securement to an underlying support. In the past, sections of grating have been either fixably bolted or welded in place. Both fastening techniques are time-consuming and expensive in terms of labor. The use of bolts requires that holes be drilled in the underlying support member, creating a weak spot subject to rusting and other corrosion damage. In certain situations, the sections of grating must be removable for access to areas beneath the floor or walkway.
This has created the need for a releasable anchoring fastener for anchoring sections of grating to an underlying support.
Representative grating fasteners are illustrated by U.S. Pat. No. 4,180,343 issued Dec. 25, 1979 to Glen Finlay and entitled "Grating Fastener"; U.S. Pat. No. 3,367,078 issuing Feb. 6, 1968 to J. B. Thompson Jr., and entitled "Fastening Device For Expanded-Metal Sheets"; and U.S. Pat. No. 2,467,877 issued Apr. 19, 1949 to R. J. Barry and entitled "Fastening Device".
Each of these grating fasteners employ a threaded screw or bolt which has a headed end projecting through a hole within a base portion of a hook member, plate or saddle clip. The shank of the screw or bolt project through a hole within a foot of narrow, elongated form, capable of passing through a slot between parallel bars of the grating. The foot at one end contacts the surface of a support member flange opposite that contacting the grating itself, while the opposite end thereof includes means integral with or affixed thereto for contacting one or more of the cross-bars to the side thereof opposite the screw or bolt forming the connection between the hook element and the foot.
While such fasteners have performed adequately and while they releasably secure the grating to an underlying support, where the grating is subjected to vibration, it has a tendency to loosen. Further, since the bolt or screw is threaded either into a nut on the face of the foot opposite that of the hook element to lock the hook element to one or more parallel bars and the foot to the support flange at one end and one or more of the bottom of the parallel bars by tensioning of the bolt or screw, such requires the threading the screw or bolt to the threaded hole within the foot, or the nut threadably carrying the same, which takes considerable time, preventing quick installation. Further in some cases access to the slot within the headed end of the screw or nut is difficult, if not impossible.
It is therefore a primary object of the present invention to provide an improved grating fastener which maintains the hook element in contact with the foot via a compression coil spring under slight compression for proper alignment of the components of the fastener assembly which insures the spring tensioning of the hook element over the top of at least one of the grating parallel bars and one end of the foot against the bottom of said one cross bar and the opposite end against the bottom of the support flange where the tensioned grating fastener may have the foot projected through the opening between laterally spaced cross bars permits the foot to be rotated into opposite end engagement with the bottom of the cross bar and the support flange by increasing the compression of the spring and shifting of the hook element at its base relative to the compression coil spring, and wherein the compression of the coil spring maintains the coupling between the grating and the support under an effective heavy, resilient tension bias.